1. Department of Molecular Biotechnology, WCU Program, Konkuk University, Seoul 143-701, Korea
2. Faculty of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
3. Division of Mass Spectrometry Research, Korea Basic Science Institute, Ochang 863-883, Korea
4. Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon 305-764, Korea
5. Department of Applied Biochemistry, Konkuk University, Chungju, Chungbuk, Korea